What to do when your roof is leaking

10 April 2023

What to do when your roof is leaking

It’s estimated that 40% of all building issues are caused by water intrusion, so if your commercial building has a leaking roof, time is of the essence.

Commercial roofs are much more complex than the average residential roof. With detailing, projections, skylights, flashings and more, all it takes is one weak link in the chain. 

Left untreated, leaky roofs can result in significant internal and structural damage, not to mention disruption and loss of earnings. Therefore, it’s essential to contact a commercial roofing expert as soon as you suspect a leak.  

At FHS Roofing, we’ve been caring for Canterbury businesses for over 95 years. Our roof maintenance and leak investigation services are a safety net that many local companies rely on, and our Christchurch roofers don’t take that lightly. 

Whether you own or lease your property, FHS Roofing can help you address and prevent leaks so that you can focus on the bigger picture. 

Why do commercial roofs leak?

Commercial roofs can leak for a number of reasons, but in 90% of cases, leaks are caused by failed or poorly installed flashings. Damaged membranes and lack of proper maintenance are the main contributors to a leaking roof, but it’s generally poor installation of flashings that is the most common cause. 

For this reason, flashings are one of the first areas our team inspect when diagnosing leaks. We use industry-leading techniques to assess roof issues and find the source of the problem quickly. We also use cutting-edge roofing materials and products to ensure the leak is repaired correctly.

What to do when your roof is leaking
If you’ve spotted a telltale drip, noticed puddling on the floor or are experiencing increased dampness indoors, you may have a leaky roof. There are four steps you should take immediately to help minimise damage.

Step 1: Locate the leak

Pinpointing the location of a leak is often easier said than done, which is why our leak investigation service is so popular. Whether you’re carrying out this step yourself or calling in the professionals, the more information you can gather, the better. 

Internally, the signs to look out for are blistering and stains on walls/ceilings or an unpleasant odour. Externally, the leak may stem from flashing, clogged gutters, damaged roof membrane or inadequate drainage. If you locate the leak, mark it with a bright marker, like waterproof tape. This will help the contractors fix the problem more efficiently.  

Remember, climbing onto a roof poses a significant risk to your wellbeing, so it shouldn’t be attempted without the appropriate safety equipment. If in doubt, ask for help. 

‍Step 2: Minimise the damage

Damage control is a must when dealing with a leak. Even a small leak can create widespread damage, especially if it worsens outside of business hours or if a sudden downpour exacerbates the issue. 

Before you begin thinking about fixing the leak, remove everything you can from the area and protect sensitive equipment or supplies. If it’s not possible to remove your equipment from the room, cover it with a waterproof cover or tarpaulin. A large container can be left under the leak to contain the spread of water and prevent further damage.  

It’s worth considering keeping staff out of the area if the issue isn’t able to be fixed immediately. The moisture created by a leak brings with it a risk of mould, particularly if there’s poor circulation. So try to keep the area as isolated as possible. 

‍Step 3: Find the best commercial roofers

Now that you’ve done everything you can, it’s time to bring in a trusted roofing company. Look for a well-established firm with positive reviews from people in your area. For commercial buildings, it’s also important to remember that residential and commercial roofs differ greatly. 

A commercial roofing company will know how to identify the leak and can provide options for rectifying the issues. They’ll also provide quotes for you to discuss with any relevant parties. 

‍Step 4: Get in touch with your insurance company

Once the leak is no longer an issue, get in touch with your insurance agent. They can explain if your policy covers any interior damage and associated roofing services or replacement, while also helping review whether the manufacturer's warranty will cover leakage issues.

Read our FAQ below for common questions about insurance and who is responsible for a leaking roof in a commercial property.

How to prevent commercial roof leaks in the future

To keep your commercial roof in prime condition, frequent maintenance is key. At FHS Roofing, we are proud to provide reliable and effective Christchurch roof maintenance services - so you can enjoy the peace of mind that comes from knowing your property is protected from potential damage caused by leaks.

From moss killing and roof washing to gutter cleaning and downpipe unblocking, we’ll ensure your commercial roof is in great shape and that any potential issues are noticed early. 


Who is responsible for repairs on a commercial lease in NZ?

Commercial landlords typically manage structural repairs such as foundations, flooring, roof and exterior walls, while tenants take ownership of non-structural and internal issues like air conditioning or plumbing. 

So, in the event of a roof leak, the landlord would generally be responsible for rectifying the problem. 

Is a leaking roof a safety hazard?

Working in a room with leak damage poses a safety hazard both in terms of mould inhalation and hidden risks. Weakened ceilings can collapse without warning and cause physical injury either through the fall itself or from inhalation or ingestion of the fine particles released in the crash.

On commercial roofs, gutters can be badly contaminated, so its a good idea to contain the water and avoid touching it without gloves. Run-off from asbestos roofs is another hazard to watch out for. 

Is a leaking roof an emergency?

A leaking roof is absolutely an emergency, regardless of how small or large the leak may initially seem. A small leak can escalate unpredictably, and leaks of all sizes can damage the structural safety of your building. 

Will insurance cover the leak?

Insurance generally covers roof leaks, depending on the issue's source. If it's an unforeseen incident or natural disaster, many insurers will cover repair costs associated with damage caused by a leak. However, insurance may not pay out if negligence is to blame for the problem - such as from lack of maintenance or upkeep.

Policy exclusions for roof leak damages may include:

  • Roof neglect
  • Lack of maintenance
  • Mould, algae, or rot
  • General roof deterioration
  • Insect, rodent or bird damage


When should I call my insurance provider?

Before involving your insurance company, we recommend calling a professional roofing service like FHS Roofing for an assessment of the damage and advice on which next steps are most appropriate. We have considerable experience dealing with insurance companies - saving you time and hassle!

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